Image content transmission method and apparatus using edge computing service

1 . A method, performed by an edge data network, of transmitting image content, the method comprising:

obtaining orientation information from an electronic device connected to the edge data network;

obtaining a first partial image including a user field-of-view image corresponding to the orientation information and an extra field-of-view image neighboring the user field-of-view image;

generating a first user field-of-view frame by encoding the user field-of-view image using at least one first encoding parameter;

generating a first extra field-of-view frame by encoding the extra field-of-view image using at least one second encoding parameter;

transmitting, to the electronic device, user field-of-view image packets including user field-of-view frame packets including information about the first user field-of-view frame, and first transmission error control packets;

transmitting, to the electronic device, extra field-of-view image packets including extra field-of-view frame packets including information about the first extra field-of-view frame, and second transmission error control packets;

receiving, from the electronic device, a request for retransmission of a user field-of-view packet that the electronic device fails to recover; and

based on the request for retransmission, retransmitting, to the electronic device, the user field-of-view packet that the electronic device fails to recover,

wherein the request for retransmission is received from the electronic device when it is predicted that the user field-of-view packet that the electronic device fails to recover can be received before completion of decoding of the first user field-of-view frame, and based on a result of identifying, by the electronic device, whether at least a part of an area related to the user field-of-view packet that the electronic device fails to recover is included in a latest user field-of-view area based on latest orientation information of the electronic device.

2 . The method of claim 1 , wherein the user field-of-view image comprises an image having a user field-of-view, which is identified based on information about a viewport area of a display of the electronic device, with respect to a position in a virtual reality (VR) image indicated by the orientation information, and

the extra field-of-view image is an image having an extra field-of-view in up, down, left, and right directions of the user field-of-view image.

3 . The method of claim 1 , wherein the first partial image comprises a partial image in a first VR image having a certain frame index of a VR sequence including a plurality of frames, and the first partial image is related to the orientation information indicating a position of the partial image.

4 . The method of claim 1 , wherein the user field-of-view image packets are transmitted to the electronic device through a first transport channel, and the extra field-of-view image packets are transmitted to the electronic device through a second transport channel, and

the first and second transmission error control packets are forward error correction (FEC) packets.

5 . The method of claim 4 , wherein the first encoding parameter and the second encoding parameter are at least one of a bit rate, a frame rate, or a resolution, which are identified based on at least one of a required latency, an available bandwidth, a number of consecutive lost packets, a packet loss rate, or a round trip time (RTT), and

transmission parameters including at least one of an FEC code rate or an FEC block size, which are related to the FEC packets, include at least one of an FEC code rate or an FEC block size, which are identified based on at least one of a required latency, an available bandwidth, a number of consecutive lost packets, a packet loss rate, or an RTT.

6 . The method of claim 4 , wherein the transmitting of the user field-of-view image packets to the electronic device comprises:

based on a packet loss rate, a number of consecutive lost packets, an available bandwidth, and a required time period based on a frame rate and a required latency, identifying source packets including at least some of the user field-of-view frame packets, a size of an FEC block including the FEC packets, and an FEC code rate indicating a ratio of the source packets to the FEC block;

identifying a number of FEC blocks based on a number of the user field-of-view frame packets and a number of the source packets;

based on the number of the FEC blocks, modifying the number of source packets included in each FEC block; and

based on the modified number of the source packets included in each FEC block, obtaining the FEC blocks.

7 . The method of claim 6 , wherein a frame rate of the first user field-of-view frame and a bit rate per frame of the first user field-of-view frame are identified based on the FEC code rate, Rfps, Rfbr, and an available bandwidth of the electronic device,

wherein Rfps denotes a frame rate of the first extra field-of-view frame compared to the first user field-of-view frame, and Rfbr denotes a bit rate per frame of the first extra field-of-view frame compared to the first user field-of-view frame,

the frame rate of the first extra field-of-view frame is identified based on a frame rate of a user field-of-view area and Rfps, and

the bit rate per frame of the first user field-of-view frame is identified based on the bit rate per frame of the first extra field-of-view frame and Rfbr.

8 . The method of claim 1 , wherein the

request for retransmission is further based on at least one of a number of the packet that the electronic device fails to recover among the user field-of-view frame packets, a time period remaining until decoding of the user field-of-view image related to the packet that the electronic device fails to recover, or an RTT.

9 . The method of claim 1 , wherein state information is received from the electronic device when the edge data network is connected to the electronic device every first period, the state information including at least one of information about a viewport area of a display of the electronic device, information about a frame rate of the first extra field-of-view frame compared to the first user field-of-view frame, information about a bit rate per frame of the first extra field-of-view frame compared to the first user field-of-view frame, or information about a required latency,

channel state information is received from the electronic device every second period, the channel state information indicating at least one of a number of consecutive lost packets, a packet loss rate, or an available bandwidth, and

periodically measured RTT information is received from the electronic device every third period.

10 . The method of claim 1 , wherein the first partial image comprises data units of a preset field-of-view range,

the generating of the first user field-of-view frame comprises:

obtaining a first data unit of at least one preset field-of-view range corresponding to the user field-of-view image in the first partial image; and

generating the first user field-of-view frame by encoding the first data unit of the at least one preset field-of-view range, and

the generating of the first extra field-of-view frame comprises:

obtaining a second data unit of at least one preset field-of-view range corresponding to the extra field-of-view image in the first partial image; and

generating the first extra field-of-view frame by encoding the second data unit of the at least one preset field-of-view range.

11 . The method of claim 1 , wherein a time until completion of decoding is determined based on a remaining time of a timer of the electronic device.

12 . An edge data network for transmitting image content to an electronic device, the edge data network comprising:

a network interface;

memory storing one or more instructions; and

at least one processor, comprising processing circuitry, configured, individually or collectively, to execute the one or more instructions and to control the edge data network to:

obtain orientation information from an electronic device connected to the edge data network, obtain a first partial image including a user field-of-view image corresponding to the orientation information and an extra field-of-view image neighboring the user field-of-view image,

generate a first user field-of-view frame by encoding the user field-of-view image using at least one first encoding parameter, generate a first extra field-of-view frame by encoding the extra field-of-view image using at least one second encoding parameter,

transmit, to the electronic device, user field-of-view image packets including user field-of-view frame packets including information about the first user field-of-view frame, and first transmission error control packets,

transmit, to the electronic device, extra field-of-view image packets including extra field-of-view frame packets including information about the first extra field-of-view frame, and second transmission error control packets,

receive, from the electronic device, a request for retransmission of a user field-of-view packet that the electronic device fails to recover, and

based on the request for retransmission, retransmit, to the electronic device, the user field-of-view packet that the electronic device fails to recover,

wherein the request for retransmission is received from the electronic device when it is predicted that the user field-of-view packet that the electronic device fails to recover can be received before completion of decoding of the first user field-of-view frame, and based on a result of identifying, by the electronic device, whether at least a part of an area related to the user field-of-view packet that the electronic device fails to recover is included in a latest user field-of-view area based on latest orientation information of the electronic device.

13 . The edge data network of claim 12 , wherein the user field-of-view image packets are transmitted to the electronic device through a first communication channel, and the extra field-of-view image packets are transmitted to the electronic device through a second communication channel, and

the first and second transmission error control packets are forward error correction (FEC) packets.

14 . The edge data network of claim 13 , wherein the first encoding parameter and the second encoding parameter are at least one of a bit rate, a frame rate, or a resolution, which are identified based on at least one of a required latency, an available bandwidth, a number of consecutive lost packets, a packet loss rate, or a round trip time (RTT), and

transmission parameters including at least one of an FEC code rate or an FEC block size, which are related to the FEC packets, include at least one of an FEC code rate or an FEC block size, which are identified based on at least one of a required latency, an available bandwidth, a number of consecutive lost packets, a packet loss rate, or an RTT.

15 . The edge data network of claim 13 , wherein the request for retransmission is further based on at least one of a number of the packet that the electronic device fails to recover among the user field-of-view frame packets, a time period remaining until decoding of the user field-of-view image including the packet that the electronic device fails to recover, or an RTT.

16 . A non-transitory computer-readable storage medium storing instructions which, when executed by at least one processor, cause the at least one processor to control an edge data network to perform operations comprising:

obtaining orientation information from an electronic device connected to the edge data network;

obtaining a first partial image including a user field-of-view image corresponding to the orientation information and an extra field-of-view image neighboring the user field-of-view image;

generating a first user field-of-view frame by encoding the user field-of-view image using at least one first encoding parameter;

generating a first extra field-of-view frame by encoding the extra field-of-view image using at least one second encoding parameter;

transmitting, to the electronic device, user field-of-view image packets including user field-of-view frame packets including information about the first user field-of-view frame, and first transmission error control packets;

transmitting, to the electronic device, extra field-of-view image packets including extra field-of-view frame packets including information about the first extra field-of-view frame, and second transmission error control packets;

receiving, from the electronic device, a request for retransmission of a user field-of-view packet that the electronic device fails to recover; and

based on the request for retransmission, retransmitting, to the electronic device, the user field-of-view packet that the electronic device fails to recover,

wherein the request for retransmission is received from the electronic device when it is predicted that the user field-of-view packet that the electronic device fails to recover can be received before completion of decoding of the first user field-of-view frame, and based on a result of identifying, by the electronic device, whether at least a part of an area related to the user field-of-view packet that the electronic device fails to recover is included in a latest user field-of-view area based on latest orientation information of the electronic device.